Now showing items 70-89 of 100

    Phonons in III-nitride thinfilms, bulk and nanowires: a closer look into InN vibrational properties 

    Domènech i Amador, Núria (Date of defense: 2015-10-30)

    This thesis is devoted to the study of the interactions of phonons in indium nitride (InN) and materials of the (In,Ga)N system with wurtzite structure. For this purpose, we present Raman spectroscopy on nanowires (NWs), ...

    Preparation of high efficiency Cu2ZnSn(S,Se)4solar cells based on a single-step sulfo-selenization process 

    Xie, Haibing (Date of defense: 2016-11-21)

    Cu2ZnSn(S,Se)4 (CZTSSe) kesterite semiconductors have been proposed as a potential medium to long term replacement of Cu(In,Ga)(S,Se)2 (CIGS) chalcopyrites for sustainable cost-efficient thin film technologies compatible ...

    Quantitative methods for electron energy loss spectroscopy 

    Eljarrat Ascunce, Alberto (Date of defense: 2015-10-21)

    This thesis explores the analytical capabilities of low-loss electron energy loss spectroscopy (EELS), applied to disentangle the intimate configuration of advanced semiconductor heterostructures. Modern aberration corrected ...

    Raman scattering based strategies for assessment of advanced chalcopyrite photovoltaic technologies: Characterisation of electrodeposited Cu(In,Ga)(S,Se)2 solar cells 

    Insignares, Cristina (Date of defense: 2015-11-13)

    The main objective of this thesis is the development of Raman scattering based methodologies for the analysis of advanced electrodeposition-based CIGS technologies, with the identification and characterization of parameters ...

    Rare earth- and Si nanostructure-based light emitting devices for integrated photonics 

    Berencén Ramírez, Yonder Antonio (Date of defense: 2014-10-23)

    This thesis presents experimental work on developing rare-earth ions and Si nanostructures as a material platform for light emitting devices (LEDs) in the visible and near-infrared range. The realization of the different ...

    Rare Earth-Doped Silicon-Based Light Emitting Devices: Towards new Integrated Photonic Building Blocks 

    Ramírez, Joan Manel (Date of defense: 2015-07-02)

    This thesis presents the work carried out towards the implementation of RE-doped Si-based light emitting devices as integrated optoelectronic building blocks for Silicon Photonics. This work spans from the fundamentals ...

    Routing algorithms for wireless sensor : networks based on the duty cycle of its components 

    Daemitabalvandani, Maziyar (Date of defense: 2016-02-01)

    Wireless sensor network is one of the most important topics in the current data transferring. In fact regarding to data gathering and transformation, cost effective is the top topic and optimum point, which every vendors ...

    Shape Control and Functional Properties of Copper Chalcogenide Colloidal Nanocrystals 

    Li, Wenhua (Date of defense: 2013-10-01)

    The high quality CuxS nanocrystals were synthesized (Chapter 3) and the profound understanding and skills to prepare colloidal nanocrystals has been obtained and improved. It revealed a very simple synthetic route not only ...

    Signal Processing Approaches to the Detection and Localization of Gas Chemical Sources using Partially Selective Sensors 

    Pomareda Sesé, Victor (Date of defense: 2013-07-23)

    Due to recent progress, higher-order chemical instrumentation provides large amounts of data which need automated processing in order to extract relevant information. In most cases, the raw signals or spectra are too complex ...

    Silicon Nanocrystal Superlattices for Light-Emitting and Photovoltaic Devices 

    López Vidrier, Julià (Date of defense: 2015-07-16)

    During the last decades, silicon nanocrystals have focused great attention due to the size-dependent physical properties they present, attributed to the quantum confinement effect. This, added to the bulk silicon compatibility ...

    Sistemas nanoestructurados y propiedades de transporte en capas delgadas de manganita 

    Peña Guédez, Luis Alejandro (Date of defense: 2014-04-24)

    En esta memoria se recogen los resultados sobre preparación y caracterización de las propiedades físicas de sistemas magnéticos nanoestructurados. Para la fabricación de las nanoestructuras se han empleado dos estrategias ...

    Síntesi i caracterització d’òxid de titani nanoestructurat per aplicacions energètiques 

    Fàbrega Gallego, Cristian (Date of defense: 2011-09-16)

    La tesi s’engloba en un context energètic en el que les tendències actuals del subministrament i el consum d’energia són clarament insostenibles. No és exagerat dir que el futur de la prosperitat de la humanitat depèn de ...

    Síntesi, caracterització i aplicacions d'òxids metàl·lics nanoestructurats 

    Rossinyol Casals, Emma (Date of defense: 2008-01-31)

    Aquest treball es va iniciar amb la intenció de millorar les propietats sensores d'alguns òxids metàl·lics tan a partir del control del creixement dels cristalls en el cas de capes fines, com en l'augment de la superfície ...

    Síntesis química de capas buffer para nuevas tecnologías de calcogenuros con aplicaciones fotovoltaicas 

    Sánchez González, Yudania (Date of defense: 2016-03-16)

    En éste trabajo de Tesis se presentan los resultados más relevantes obtenidos en el desarrollo de capas buffer de CdS y de capas buffer libres de cadmio (sulfuro de indio y sulfuro de zinc) preparadas mediante la técnica ...

    Smart Chemical Sensors: Concepts and Application 

    Udina Oliva, Sergi (Date of defense: 2012-07-13)

    This PhD thesis introduces basic concepts of smart chemical sensors design, which are afterwards applied to a particular application: the analysis of natural gas. The thesis addresses thus two sets of objective, a first ...

    Smart materials for microrobotics motion control and power harvesting 

    Brufau Penella, Jordi (Date of defense: 2009-01-30)

    This thesis focuses on the use of smart materials in microrobotic applications. The development of materials with the capabilities to mechanically respond to electrical stimuli or, at the same time, to electrically respond ...

    Solution Growth and Functional Properties of Vertically Aligned ZnO Nanowires 

    Fan, Jiandong (Date of defense: 2013-07-19)

    This dissertation has focused on three main topics: (1) Synthesis and characterization of ZnO:Cl NWs; (2) Hetero and homo nanostructures based on ZnO:Cl NWs for efficient PEC cells; (3) Photovoltaic performance of DSCs ...

    Solution-Processing of Chalcogenide Nanoparticles and Thin Films for Photovoltaic Applications 

    Carreté, Àlex (Date of defense: 2015-05-29)

    Thin film solar cells based on direct band gap semiconductors have attracted much research during last decades. Thin film technologies are currently commercial and display record power conversion efficiencies up to 20% at ...

    Structural analysis for the improvement of SnO(2) based gas sensors 

    Diéguez Barrientos, Àngel (Date of defense: 1999-09-29)

    La investigación presentada está centrada en la mejora de sensores de gas conductométricos de Sn02. Se analizan sensores en capa gruesa y en capa delgada. En el primer caso, el polvo de Sn02 necesario para fabricar los ...

    Structure nanoengineering of functional nanomaterials. Advanced electron microscopy study 

    Zamani, Reza (Date of defense: 2013-11-04)

    In this report novel materials for advanced applications are studied by means of the latest microscopy technologies and methodologies which have had a dramatic impact on progress of materials science. The aim was to study ...